South Moreton is a village and civil parish situated in South Oxfordshire, England, within the United Kingdom. It lies approximately three miles east of Didcot, four miles west of Wallingford, and seven miles south of Abingdon. The settlement is positioned on a ridge above the moor of Hakka's Brook, now known as Hagbourne or Hadden Marsh. Geographically, it is separated from its twin village of North Moreton by only a quarter of a mile to the north, with the Great Western Railway cutting forming the boundary between them.

The name South Moreton derives from the Domesday Book entry for Moretune, referring to houses on the ridge. In 1086, the book recorded five manors in the area, including Saunderville, Huse or Bray, Adresham, and Fulscot. The parish remained part of Berkshire until boundary changes in 1974 transferred it to Oxfordshire. The South Moreton Inclosure Act of 1818 significantly shaped land ownership, with Henry Hucks Gibbs, 1st Baron Aldenham, becoming the main landlord for many inclosures during this period.

The village features large old houses on the High Street, newer cottages to the east, and modern social housing to the west. Many of the older cottages are thatched, dating from the seventeenth century. Notable landmarks include The Hall, a walled Victorian estate and the last working farm in the village, and Saunderville, a moated manor house visible from the railway. The Church of England parish church of Saint John the Baptist stands by ancient earthworks at the southwestern edge, while a Strict Baptist chapel occupies a central position on the High Street.

Cultural life includes services at the parish church held only on major feast days and other arranged occasions. The village supports a community-owned pub, The Crown Inn, which was saved from redevelopment in the late 2010s by the South Moreton Community Benefit Society. This society lobbied to designate the building as an Asset of Community Value and reopened it in May 2019. The community also maintains a primary school and benefits from historical records preserved in The Rector's Book, which documents memories extending back to 1845.

The population was recorded as 326 in 2021, following a previous census count of 420 in 2011. The local economy historically involved meat supply to London via the Great Western Railway, with land holdings still owned by descendants of early investors. Transport links include Thames Travel route 94 connecting to Didcot and Didcot Parkway railway station. Didcot Parkway offers frequent services to London Paddington, while Cholsey railway station provides connections between Reading, Oxford, and the region.